RestSharp 將 IRestResponse.StatusCode == 0 返回給 Polly onRetry

Question

我圍繞 RestSharp 客戶端編寫了一個相當簡單的包裝器，使用 Polly 向它添加了一些重試邏輯。 我設置了 Fiddler 來測試它並模擬了一些“不良”響應。

我的問題是在onRetry委托，對result.Result.StatusCode位似乎有時記錄為0，而不是實際的糟糕狀態代碼（在我的一些testings 502）。

但是，通過我的單元測試，它似乎工作得很好。 也許這里的比賽條件？

知道為什么會這樣嗎？

提前致謝。

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Polly;
using RestSharp;
using System;
using System.Collections.Generic;
using System.Net;

namespace FundsAFE.Graphite
{
    public class RequestExecutor
    {
        private static readonly NLog.Logger logger = NLog.LogManager.GetCurrentClassLogger();

        private IRestClient client;
        private IRestRequest request;
        private Policy<IRestResponse> retryPolicy;

        public IRestResponse LastErrorResponse { get; set; }

        private static readonly List<HttpStatusCode> invalidStatusCodes = new List<HttpStatusCode> {
            HttpStatusCode.BadGateway,
            HttpStatusCode.Unauthorized,
            HttpStatusCode.InternalServerError,
            HttpStatusCode.RequestTimeout,
            HttpStatusCode.BadRequest,
            HttpStatusCode.Forbidden,
            HttpStatusCode.GatewayTimeout
        };


        public RequestExecutor(IRestClient client, IRestRequest request)
        {
            this.client = client;
            this.request = request;
        }

        public IRestResponse Execute(int retryCount, int delay)
        {

            retryPolicy = Policy                
                .HandleResult<IRestResponse>(resp => invalidStatusCodes.Contains(resp.StatusCode) || !IsValidJson(resp))                
                .WaitAndRetry(retryCount, i => TimeSpan.FromMilliseconds(delay), (result, timeSpan, currentRetryCount, context) =>
                {
                    //Status code here is sometimes 0???
                    logger.Error($"Request failed with {result.Result.StatusCode}. Waiting {timeSpan} before next retry. Retry attempt {currentRetryCount}");
                    LastErrorResponse = result.Result;
                });

            var policyResponse = retryPolicy.ExecuteAndCapture(() =>
            {
                var url = client.BuildUri(request);
                logger.Debug(url.ToString());
                var response = client.Execute(request);
                return response;
            });
            if(policyResponse.Result != null)
            {
                return policyResponse.Result;
            } else
            {
                return LastErrorResponse;
            }
        }

        public static bool IsValidJson(IRestResponse response)
        {
            if (response.Content.Length == 0)
            {
                //Empty response treated as invalid
                return false;
            }
            try
            {
                var parsed = JObject.Parse(response.Content);
            }
            catch (JsonReaderException e)
            {
                //Will catch any mallformed json
                return false;
            }
            return true;
        }
    }
}


using Microsoft.VisualStudio.TestTools.UnitTesting;
using FundsAFE.Graphite;
using Moq;
using RestSharp;
using System.Net;
using FluentAssertions;
using System;
using FluentAssertions.Extensions;

namespace FundsAFE.Test.Moq
{
    [TestClass]
    public class MoqUnitTestRequest
    {

        public Mock<IRestClient> CreateMockClientWithStatusCodeAndContent(HttpStatusCode code, string content)
        {
            Mock<IRestClient> mockClient = new Mock<IRestClient>();
            mockClient.Setup(c => c.Execute(It.IsAny<IRestRequest>())).Returns(
                new RestResponse
                {
                    Content = content,
                    StatusCode = code
                }
            );

            mockClient.Setup(c => c.BuildUri(It.IsAny<IRestRequest>())).Returns(
                new Uri("http://fake.fake")
            );

            return mockClient;
        }

        [DataTestMethod]
        [DataRow(HttpStatusCode.BadGateway)]
        [DataRow(HttpStatusCode.Unauthorized)]
        [DataRow(HttpStatusCode.InternalServerError)]
        [DataRow(HttpStatusCode.RequestTimeout)]
        [DataRow(HttpStatusCode.BadRequest)]
        [DataRow(HttpStatusCode.Forbidden)]
        [DataRow(HttpStatusCode.GatewayTimeout)]
        public void TestBadStatusCodesAndRetry(HttpStatusCode httpStatusCode) {
            //Arrange
            Mock<IRestRequest> mockRequest = new Mock<IRestRequest>();
            Mock<IRestClient> mockClient = CreateMockClientWithStatusCodeAndContent(httpStatusCode, "fakecontent");
            RequestExecutor requestExecutor = new RequestExecutor(mockClient.Object, mockRequest.Object);

            int retries = 10;
            int delay = 50;
            int totalWaitTime = (retries * delay) - 10; //10ms error margin

            //Act and Verify            
            var response = requestExecutor.Execute(retryCount: retries, delay: 101);
            mockClient.Verify(x => x.Execute(It.IsAny<IRestRequest>()), Times.Exactly(retries + 1)); //1st failed attempt + 10 retries = 11            

            //Assert            
            requestExecutor.ExecutionTimeOf(re => re.Execute(retries, delay)).Should().BeGreaterOrEqualTo(totalWaitTime.Milliseconds());
            response.Should().NotBeNull();
            response.StatusCode.Should().Be(httpStatusCode);
            requestExecutor.LastErrorResponse.StatusCode.Should().Be(httpStatusCode);
        }

        [DataTestMethod]
        //Empty content
        [DataRow("")]
        //Missing closing quote
        [DataRow("{\"fruit\": \"Apple,\"size\": \"Large\",\"color\": \"Red\"}")]
        //Missing angle bracket
        [DataRow("\"q1\": {\"question\": \"Which one is correct team name in NBA?\",\"options\": \"New York Bulls\",\"Los Angeles Kings\",\"Golden State Warriros\",\"Huston Rocket\"],\"answer\": \"Huston Rocket\"}")]
        //Missing curly bracket
        [DataRow("\"sport\": {\"q1\": {\"question\": \"Which one is correct team name in NBA?\",\"options\": \"New York Bulls\",\"Los Angeles Kings\",\"Golden State Warriros\",\"Huston Rocket\"],\"answer\": \"Huston Rocket\"}")]
        public void TestBadContentRetries(string content)
        {

            //Arrange
            Mock<IRestRequest> mockRequest = new Mock<IRestRequest>();
            Mock<IRestClient> mockClient = CreateMockClientWithStatusCodeAndContent(HttpStatusCode.OK, content);
            RequestExecutor requestExecutor = new RequestExecutor(mockClient.Object, mockRequest.Object);

            int retries = 10;
            int delay = 50;
            int totalWaitTime = (retries * delay) - 10; //10ms error margin

            //Act and Verify            
            var response = requestExecutor.Execute(retryCount: retries, delay: delay);
            mockClient.Verify(x => x.Execute(It.IsAny<IRestRequest>()), Times.Exactly(retries + 1)); //1st failed attempt + 10 retries = 11            

            //Assert            
            requestExecutor.ExecutionTimeOf(re => re.Execute(retries, delay)).Should().BeGreaterOrEqualTo(totalWaitTime.Milliseconds());
            response.Should().NotBeNull();

        }
    }
}

Answer 1

好像有情況下（例如它看起來從RESTsharp源代碼一些例外情況），其中RESTsharp很可能會回到你的IRestResponse與resp.StatusCode == 0 。

onRetry的日志代碼可能應該檢查onRetry上更廣泛的狀態屬性IRestResponse ，而不僅僅是IRestResponse.StatusCode